TRUCK-TRACTOR AND SEMITRAILER
7 . 1 CHECKING A
SEMITRAILER. Before coupling a semitrailer to a
truck-tractor equipped with vacuum or air operated
brakes, make the following checks:
(1) Are the air hoses serviceable?
(2) Are the coupling and braking equipment in
proper working order?
(3) Are the couplings, including seals, clean and
(4) Are the cutout valves in proper order?
(5) Are the semitrailer king pin, locking device,
and coupling functioning properly?
(6) Is the tractor's fifth wheel properly lubricated
and moving freely?
7.2 C O U P L I N G THE TRUCK-TRACTOR TO THE
SEMITRAILER. T o couple the truck-tractor to the
semitrailer, proceed as follows:
(1) Place wheel chocks in front of and behind the
(2) Make sure the fifth wheel hook is open; then,
back the tractor close enough to the trailer to permit
coupling of the brake lines.